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Vulnerability · Published Feb 26, 2025 · Assigned by Linux

CVE-2021-47649udmabuf: validate ubuf->pagecount

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 83.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: udmabuf: validate ubuf->pagecount Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The problem was in ubuf->pages == ZERO_PTR. ubuf->pagecount is calculated from arguments passed from user-space. If user creates udmabuf with list.size == 0 then ubuf->pagecount will be also equal to zero; it causes kmalloc_array() to return ZERO_PTR. Fix it by validating ubuf->pagecount before passing it to kmalloc_array().

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.17.3-1DEBIAN-CVE-2021-47649
Debian:13linux5.17.3-1DEBIAN-CVE-2021-47649
Debian:14linux5.17.3-1DEBIAN-CVE-2021-47649
Ubuntu:22.04:LTSlinux5.15.0-37.39UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-aws5.15.0-1011.14UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-azure5.15.0-1010.12UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-gcp5.15.0-1008.12UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-gke5.15.0-1008.10UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-ibm5.15.0-1007.8UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1008.11UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-kvm5.15.0-1010.11UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-37.39UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-oracle5.15.0-1009.12UBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-raspi5.15.0-1011.13UBUNTU-CVE-2021-47649
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2021-47649
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2021-47649

Affected products (as reported)

VendorProductVersions
Linux Linux fbb0de795078190a9834b3409e4b009cfb18a6d4 – before 5d50f851dd307c07ca5591297093f19967c834a9fbb0de795078190a9834b3409e4b009cfb18a6d4 – before b267a8118c2b171bf7d67b90ed64154eeab9fae0fbb0de795078190a9834b3409e4b009cfb18a6d4 – before 811b667cefbea9cb7511a874b169d6a92907137efbb0de795078190a9834b3409e4b009cfb18a6d4 – before a3728d32fc61eb0fe283cb8ff60b2c8f751e2202fbb0de795078190a9834b3409e4b009cfb18a6d4 – before 9e9b4a269f84d3230f2af84ff42322db676440d9fbb0de795078190a9834b3409e4b009cfb18a6d4 – before 2b6dd600dd72573c23ea180b5b0b2f1813405882
Linux Linux 4.20

References